In 3rd Generation Partnership Project (3GPP) that is a mobile communication system standardization project, a power saving (energy saving) technique of reducing power consumption of a network has been introduced. For example, cells managed by a radio base station are powered off (deactivated), for example, during the night in which communication traffic is small.
In 3GPP, an advanced energy saving technique is scheduled to be introduced in Release 12 (for example, see Non-Patent Literature 1). For example, when a certain cell (hereinafter, referred to as a “deactivation target cell”) is powered off, transmission power of another neighboring cell (hereinafter, referred to as “supplementary cell”) is increased. As a result, the coverage of the supplementary cell expands (coverage expansion) to supplement the coverage of the deactivation target cell (that is, area supplementation).